The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Usually, one of the communication sides, for example a first unit, sends the information to the other side, for example a second unit, only after the second unit establishes an authentic connection with the first unit, i.e. the connection is established after the second unit authenticates the first unit successfully. With the connection, when the first unit sends corresponding information to the second unit, the second unit can determine the validity of the information transmitted. Sometimes, however, before a valid communicating connection is established between two communication sides, when one side needs to send important information to the other side, no valid method can be used. For example, the keys used for performing the authentication to each other between two communication sides are out of synchronism because of some reasons, i.e. they are not consistent any more, so that the normal mutual authentication can not be performed successfully and the valid mutual authentic connection can not be established. In this situation, one communication side, for example a first unit, needs to tell the other side, for example a second unit, that the authentication key needs to be synchronized again. How does the communication first unit send to the second unit the information that the authentication keys need to be synchronized again. When receiving the information from the first unit, it is a problem for the second unit to decide whether to believe or not it is secure information rather than information of an aggressive behavior triggered by an attacker.
Further, in the future communication networks, along with the enrichment of services and the extension of network functions, the security requirement of communication between a terminal and a network or between two communication units is correspondingly increased, and the geometric series increment of the quantity of information transmitted needs more secure and convenient information transmission mode.
The existing authentication method and information transmission method are simply described hereinafter by taking the existing 3G authentication as an example, the existing authentication in 3G network is completed by the collaborative work between a Mobile Station (MS), a Mobile Switching Center/Visitor Location Register (MSC/VLR) or a Serving GPRS Support Node (SGSN) and a Home Location Register/Authentication Center (HLR/AUC), an authentication key KI is stored in a Subscriber Identity Module/Universal Subscriber Identity Module (SIM/USIM) card, and an authentication key KI which is consistent with that stored in the SIM/USIM card is stored in the HLR/AUC. The MS and the AUC respectively calculate corresponding authentication parameters according to each KI stored in them, and the MSC/VLR compares the calculated results of two sides, and the validity determination of the MS by the network is completed. A procedure of authenticating the network by the MS is included in the process. If the authentication of the network by the MS fails, the MS will return an authentication failure message to the network.
The above message sent from the MS to the network is not authorized by the network, which may not lead to a severe security problem when used for returning the authentication failure message. Under some circumstances, however, when the MS sends information to the network, a severe security problem may occur if the network can not authenticate the MS.
For example, the MS sending to the network the information not authorized by the network that relates to the key configuration and update under some circumstances may cause a severe security problem. In the prior art, the message can be sent to the network side by an Unstructured Supplementary Service Data (USSD) mode or a short message mode, which can solve the security problem of information transmission because it will trigger an authentication procedure, however, the consumption of the signaling resources is largish.
To sum up, how to transmit information conveniently while guaranteeing the communication security without increasing the existing communication protocols, signaling resources and operation costs is a problem that is worthy to be solved.